The present invention pertains to carriers supporting a spare wheel at the rear of a vehicle, as for example, a sports utility vehicle.
Vehicles of the above mentioned type present a problem when a tire must be changed as such vehicles normally are equipped with tires of a size and weight significantly greater than that of a full size automobile. In many instances a vehicle operator must accordingly rely on assistance in an emergency tire changing operation. While the term tire changing is used it is intended that in fact it is the wheel and tire mounted thereon that are changed. The spare tire and wheel are often carried externally at the rear of a sports utility vehicle with the wheel center approximately four feet above the ground, which with its weight makes its removal from the vehicle an arduous task at best for most motorists.
U.S. Pat. No. 5,104,015 shows a bumper mounted carrier which swings away from the rear of the vehicle and then downwardly towards a ground surface and necessitates some lifting of wheel assembly.
U.S. Pat. No. 4,679,717 discloses a spare wheel assembly carrier mounted on a rear bumper and which swings horizontally away therefrom without lowering of the wheel assembly to ground level, i.e., still requires lifting and lowering of the wheel assembly.
U.S. Pat. No. 5,183,192 shows a spare tire lowering apparatus with a first frame swingable away from the vehicle about an upright axis and a second frame which swings about a horizontal axis to lower a spare tire to the ground. The unit is not bumper mounted.
U.S. Pat. No. 4,561,575 discloses a trailer hitch carried spare tire carrier with a post 34 swingable about a vertical axis and then a horizontal axis to lower a spare tire and wheel to a ground surface. The user must physically maneuver the spare tire and supporting post into both raised and lowered positions.
U.S. Pat. No. 4,717,054 shows a spare tire carrier positionable about a horizontal axis; parallel to a bumper, and into ground contact. A gas charged strut at 52 aids in lifting and lowering the spare tire. A lock at 100 must be inserted into place prior to spare tire removal to prevent rapid return of pivotal upright frame members 40b and 40c to a travel position.
U.S. Pat. No. 5,967,389 is of interest in that it discloses a spare wheel rack having arms swingably carried by a post in turn supported by an end of a cross tube located subjacent one end of a rear bumper.
The present invention is directed toward a wheel assembly or spare tire carrier that facilitates lifting and lowering a vehicle wheel assembly in a controlled manner by utilization of a screw drive.
A mounting plate in place on the rear bumper carries a plate or weldment positionable about an upright pivot. An upwardly inclined arm supported by the weldment carries at its outer end the spare wheel assembly. An actuator for the arm, in one form of the invention, acts on aligned threaded shafts to lower or lift the arm and the spare wheel assembly thereon. The actuator includes a ratchet assembly to impart incremental rotation to a threaded sleeve to extend or retract the arm toward and away from a ground surface. Locking means are provided to control swinging motion of the pivotally mounted bracket. The arm is further confined against
vertical movement by a rest therefor and by the actuator. Operation of the actuator lifts and lowers the arm and wheel assembly thereon at all times in a controlled and safe manner. Alternative mounting structure includes a base plate and a bracket attachable to a vehicle frame member.
A modified form of the invention utilizes a linear actuator powered by a motor driven off the vehicle electrical system. A spring driven pin locks the arm in a vehicle travel position adjacent the vehicle bumper while a catch prevents upward separation of the pin when negative loads are imparted to the arm. A modified bracket inhibits swinging of the arm about a hinge pin axis subsequent to unlatching of the arm when the parked vehicle is other than horizontal.
Important objectives include the provision of a spare wheel assembly carrier enabling the safe lifting and lowering of the assembly from and to a ground surface without requiring physical effort beyond that of the typical male or female user; the provision of a spare tire carrier that lifts and lowers a spare tire at all times controlled by an actuator preventing sudden movement of the arm carrying a spare tire assembly which may in some vehicles exceed 150 pounds; the provision of a spare tire carrier that initially moves in a horizontal plane with locks limiting such movement; the provision of a spare tire carrier not reliant on complex mechanisms of costly construction; the provision of a spare tire carrier that utilizes arm control means to provide adequate leverage for convenient lowering and raising the spare tire; the provision of a spare tire carrier using a threaded shaft and means for imparting rotation to the shaft and axial displacement of a nut element to extend or retract a tubular shaft endwise coupled to a carrier lift arm.